7 Secrets You Might Not Know About Starfish

If you want to see a starfish in the wild, go to the seashore and look in the tide pools. This is what my son, Jack, and I did recently. We were at Acadia National Park, and we saw more than a dozen starfish in a sea cave (photo above). They were just hanging out in the tide pools, hanging around and moving to and fro.

We were fascinated with them, and we’re definitely not the only ones. Here are some cool facts about starfish from my book, The Secret Lives of Animals. How many of these did you know?

1. They have multiple names.

Is the name starfish or sea star? Both are acceptable names of this well-known ocean animal.

2. Starfish aren’t actually fish.

Many people think starfish are a type of fish, but they aren’t. They don’t have gills, scales, or fins. So don’t make the mistake of putting them in the fish family.

3. They have regeneration powers.

Starfish can regrow parts of their body! For instance, if they lose an arm, they can regrow it over time. This is called regeneration in the science world.

4. Starfish don’t really swim.

Sea stars don’t swim like a fish do. Instead, they move with the little tubes on their underside. These tubes act like little suction cups, and a single sea star can have hundreds of them.

5. Their stomachs have alien-like abilities.

Sea stars have a small mouth on their underside, but this doesn’t stop them from eating larger prey. They can actually push their stomach through their mouth to eat something bigger—and then pull it back. Starfish will eat mollusks, including clams, oysters, and mussels. And what eats them? They have to watch out for predators like sharks, rays, and crabs.

6. These sea animals aren’t always shaped like stars.

You might think all sea stars have a classic star shape with five arms, but this isn’t always the case. Sometimes they have several more arms. In fact, some have as many as forty! There are more than 2,000 types of starfish, and they can range from just a few inches to more than three feet.

7. Their armor keeps them safe.

If you look closely at a sea star, you’ll see that it is very well protected. It has little spines on the top of its body, almost like protective armor, that keep it safe from predators.